Other Parts Discussed in Thread: DM3725, TPS65023
Using the DM3725 I2C4 (SmartReflex dedicated I2C), I'm trying to manually command a TPS65023 using the bypass register: PRM_VC_BYPASS_VAL. This seems very straight forward but I just can't get it to work. I'm using an oscilloscope to detect an I2C signal and also looking at the PRM_VC_BYPASS_VAL.VALID flag to go low but neither happens.
My understanding is that all I need to configure to use the I2c4 BYPASS is (1) the pad (CONTROL_PADCONF_I2C4_SCL) and (2) the Voltage Controller (PRM_VC_I2C_CFG) and then send bypass commands. I've tried numerous different register configurations without any luck and I'm therefore reaching out for help.
=> What registers need to be configured for the I2C4 BYPASS logic to work?
=> Any ideas/suggestions are greatly appreciated :)
Some notes:
- I know it's recommended to use the generic I2C's with TPS65023 but the HW is already finalized so that's not an option and in theory this should work.
- The bypass-reg VALID bit stays high which seems to indicate the logic performing the I2C isn't running.
- Scope shows SCL high and SDA low (as I expect for idle bus?).
- I've configured I2C4 pads for mode zero, disabled I2C high-speed and disabled internal pull-up.
- Both I2C4_SCL (AD26) and I2C4_SDA (AE26) are pulled up to 1.8V externally using 4k7.
- I'm aware of http://processors.wiki.ti.com/index.php/OMAP35x-AM37x-DM37x_with_TPS65023:_Design_In_Guide
